From the Old Norse personal name Rögnvaldr (composed of regin ‘advice, decision’ (also, ‘the gods’) + valdr ‘ruler’). This name was regularly used in the Middle Ages in northern England and Scotland, where Scandinavian influence was strong. It is now widespread throughout the English-speaking world.
Italian: from Coccus, a medieval personal name and nickname of uncertain derivation. De Felice speculates that it may be derived from a term of endearment, a regional variant of cucco ‘cuckoo’, also ‘old man’, or from còcco ‘egg’ (or a regional variant such as Sardinian kókku). Alternatively, it may be from Greek kokkos ‘grain’, ‘seed’, ‘pip’.